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CN-119303460-B - Downhole micro-bubble generator

CN119303460BCN 119303460 BCN119303460 BCN 119303460BCN-119303460-B

Abstract

The invention belongs to the technical field of petroleum exploitation equipment, and particularly relates to an underground micro-bubble generator. The downhole microbubble generator comprises an outer cylinder, an inner cylinder and a functional part. A microbubble generation unit configured to convert gas into microbubbles is attached to the side wall of the inner cylinder. The downhole microbubble generator provided by the invention can adapt to the downhole working environment, and can generate a large number of microbubbles for plugging and oil displacement operation only by using a physical method. The method has the advantages that the oil field recovery ratio is effectively improved, meanwhile, the use of chemical reagents such as foaming agents is avoided, the economy is better, and the method has good application prospects in the technical field.

Inventors

  • YUAN ZHOU
  • CUI XIAOJIE
  • HOU XUTIAN
  • ZHAO JIANJUN
  • YI WEIJIE
  • CHENG GUANGMING
  • NIU CHENGCHENG
  • WU ZHIYING

Assignees

  • 中国石油化工股份有限公司
  • 中石化石油工程技术研究院有限公司

Dates

Publication Date
20260512
Application Date
20230711

Claims (10)

  1. 1. A downhole microbubble generator comprising: the outer cylinder (1) comprises a first main body (11), a first air inlet (12) formed in the upper end of the first main body (11) and a grid (13) arranged on the side wall of the lower part of the first main body (11); An inner cylinder (2) arranged inside the outer cylinder (1) and comprising a second main body (21), a second air inlet (22) arranged at the upper end of the second main body (21), a first through hole (23) arranged on the side wall of the second main body (21), and a micro-bubble generating part (24) arranged on the side wall of the second main body (21) at the position corresponding to the first through hole (23), and The functional part (3) comprises a sealing plate (31) sleeved on the outer side of the inner cylinder (2) and a base (32) arranged at the bottom of the inner cylinder (2), the base (32) seals the lower end of the inner cylinder (2), the sealing plate (31) and the base (32) are both configured to be in sealing contact with the inner wall of the outer cylinder (1) and can drive the inner cylinder (2) to axially move along the inner wall of the outer cylinder (1) under the action of external force, The gas enters the inner part of the outer cylinder (1) through the first gas inlet (12) and enters the inner part of the inner cylinder (2) through the second gas inlet (22), the underground microbubble generator is configured to enable the inner cylinder (2) to move along the axial direction of the outer cylinder (1) under the action of gas pressure generated by the gas introduced into the outer cylinder (1) and the inner cylinder (2), so that the inner cylinder (2) slides from a first position at the upper part of the outer cylinder (1) to a second position at the lower part of the outer cylinder (1) and corresponding to the grid (13), and the microbubbles converted by the gas through the microbubble generating part (24) enter the underground environment through the grid (13).
  2. 2. The microbubble generator as set forth in claim 1, wherein the microbubble generation section (24) includes a microbubble filter screen (241) and a microbubble generation sheet (242).
  3. 3. The microbubble generator as set forth in claim 2, wherein the microbubble filter (241) is provided in two layers, and the microbubble generation sheet (242) is provided between the two layers of the microbubble filter (241).
  4. 4. The microbubble generator as set forth in claim 2, wherein the microbubble generation sheet (242) comprises a third body (2421) and microbubble generation holes (2422) provided in the third body (2421).
  5. 5. The microbubble generator as set forth in claim 1, wherein the gas is carbon dioxide, so that the microbubble generator can perform oil displacement operation by using carbon dioxide and carbon dioxide sealing function.
  6. 6. The microbubble generator as set forth in any one of claims 1 to 5, wherein the base (32) comprises a fourth body (321) configured in a cylindrical shape and open at both ends, an excluder ring (322) fitted over the outside of the fourth body (321) and configured to be in sealing contact with the inner wall of the outer cylinder (1), a spring (323) provided inside the fourth body (321), and a piston (324) provided at an upper end of the spring (323) and configured to be slidable inside the fourth body (321), the upper end of the piston (324) being sealingly fitted into a second through hole (25) provided at the bottom of the inner cylinder (2).
  7. 7. The microbubble generator as set forth in claim 6, wherein the second through hole (25) is provided as a stepped hole having a small inner diameter at an upper portion and a large inner diameter at a lower portion, and the piston (324) is configured as a stepped shaft adapted to the shape of the second through hole (25).
  8. 8. The microbubble generator as set forth in claim 6, characterized in that a limiting hole (14) is provided at the bottom of the outer cylinder (1), and the inner diameter of the limiting hole (14) is larger than the outer diameter of the fourth body (321).
  9. 9. The microbubble generator as set forth in claim 1, wherein a first air inlet connector (15) extending upward from the outer cylinder (1) is provided above the first air inlet (12), and a second air inlet connector (27) extending upward from the inner cylinder (2) is provided above the second air inlet (22).
  10. 10. The microbubble generator as set forth in claim 9, characterized in that a first limit bolt hole (16) is provided on the side wall of the first air intake connector (15), a second limit bolt hole (26) corresponding to the first limit bolt hole (16) is provided on the side wall of the second air intake connector (27), and the fixing of the inner cylinder (2) at the first position inside the outer cylinder (1) can be achieved by screwing limit bolts into the first limit bolt hole (16) and the second limit bolt hole (26).

Description

Downhole micro-bubble generator Technical Field The invention belongs to the technical field of petroleum exploitation equipment, and particularly relates to an underground micro-bubble generator. Background With the continuous expansion of petroleum productivity in China, reserves of good oil fields are reduced year by year, and the proportion of low-permeability and ultra-low-permeability oil reservoirs in the recoverable oil reservoirs is gradually increased. The low-permeability and ultra-low-permeability oil reservoir has the characteristics of strong non-uniformity of the stratum, easiness in damage of the reservoir, and the like. The adoption of the CO 2 technology for improving the recovery ratio is a feasible coping method. The CO 2 oil displacement technology can not only improve the utilization rate and recovery ratio of the low-permeability oil reservoir, but also realize geological sequestration of CO 2, and assist in creating green enterprises for the oil field. The carbon-to-peak carbon neutralization field project of each large energy group is established successively, but CO 2 gas channeling problems exposed in the application of the CO 2 oil displacement technology seriously affect the oil displacement and storage effects of CO 2. As a means of tertiary oil recovery commonly used at present, foam flooding is used for preventing gas channeling in the gas injection process at home and abroad at the earliest, but the CO 2 foam flooding requires a foaming agent and an auxiliary stabilizer to increase the exploitation cost, and has the defects of overlarge foam, poor injectability and the like, and the factors cause that the effect of the foam flooding applied to preventing gas channeling in a mine field cannot reach the expected level. Disclosure of Invention Aiming at the problems in the prior art, the invention provides a downhole microbubble generator. The downhole microbubble generator includes: The outer cylinder comprises a first main body, a first air inlet arranged at the upper end of the first main body and a grid arranged on the side wall of the lower part of the first main body; an inner cylinder arranged in the outer cylinder and comprising a second main body, a second air inlet arranged at the upper end of the second main body, a first through hole arranged on the side wall of the second main body, and a micro bubble generating part arranged on the side wall of the second main body and at the position corresponding to the first through hole, and The functional part comprises a sealing plate sleeved on the outer side of the inner cylinder and a base arranged at the bottom of the inner cylinder, the base forms a seal on the lower end of the inner cylinder, the sealing plate and the base are both configured to be in sealing contact with the inner wall of the outer cylinder and can drive the inner cylinder to axially move along the inner wall of the outer cylinder under the action of external force, The underground microbubble generator is configured to drive the inner cylinder to move along the axial direction of the outer cylinder under the action of air pressure generated by air introduced into the outer cylinder and the inner cylinder, so that the inner cylinder slides from a first position at the upper part of the outer cylinder to a second position at the lower part of the outer cylinder and corresponding to the grid, and microbubbles converted by the air through the microbubble generating part enter an underground environment through the grid. As an extension of the above technical solution, the present invention further provides the following embodiments: The microbubble generating part comprises a microbubble filter screen and a microbubble generating sheet. The micro-bubble filter screen is arranged in two layers, and the micro-bubble generating sheet is arranged between the two layers of micro-bubble filter screen. The microbubble generation sheet comprises a third main body and microbubble generation holes arranged on the third main body. The gas is carbon dioxide, so that the microbubble generator can realize the oil displacement operation by utilizing the carbon dioxide and the sealing function of the carbon dioxide. The base comprises a fourth main body, an isolating ring, a spring and a piston, wherein the fourth main body is in a cylindrical shape and is provided with openings at two ends, the isolating ring is sleeved outside the fourth main body and is in sealing contact with the inner wall of the outer cylinder, the spring is arranged inside the fourth main body, the piston is arranged at the upper end of the spring and is capable of sliding inside the fourth main body, and the upper end of the piston is embedded in a second through hole arranged at the bottom of the inner cylinder in a sealing mode. The second through hole is provided as a stepped hole having a small inner diameter at an upper portion and a large inner diameter at a lower portion, and the piston i